The present invention relates generally to cutting tools and, more particularly, to cutting tools having insert supporting cassettes.
In most cutting tools having replaceable cutting inserts, a cutting insert is mounted in a recess in a tool holder body and is clamped to an abutment surface by a clamp such as a screw extending through a hole in the insert into an internally threaded hole in the tool holder body. The abutment surface may be part of the tool holder body itself, or an intermediate structure such as a shim that is itself clamped to a surface formed in a recess formed on the tool holder body. In either event, design of a tool holder body is complicated when it is desired to position the insert so that a working cutting edge of the insert defines a certain angle with a longitudinal axis of the tool holder body, and so that rake and relief surfaces of the insert are properly oriented relative to the tool holder body. Once the design is completed, machining of the insert-receiving recesses in the tool holder body is likewise complicated. The finished tool holder body generally has a single function such as, for rotating tools, for example, being adapted to bore an opening having a particular diameter.
It is desirable to provide a cutting tool in which the design and machining of the tool holder body can be simplified. It is also desirable to provide a cutting tool that is more flexible in application than conventional cutting tools.
In accordance with an aspect of the present invention, a cutting tool comprises a cutting insert, the insert comprising a cutting edge, a cassette comprising an insert clamp for clamping the insert relative to an abutment surface of the cassette, and a generally cylindrical base portion, a tool holder body, the tool holder body having a cylindrical opening in which the base portion of the cassette is disposed, and a cassette clamp comprising a wedge for clamping the cassette relative to the tool holder body, the cutting edge extending beyond a periphery of the tool holder body when the insert is clamped relative to the abutment surface of the cassette and the cassette is clamped relative to the tool holder body.
In accordance with another aspect of the present invention, a cassette adapted to be mounted relative to a cutting tool comprises a body comprising an abutment surface to which an insert is adapted to be clamped by an insert clamp and a generally cylindrical base portion receivable in a cylindrical opening in a tool holder body. The abutment surface comprises an internally threaded opening for receiving a screw of the insert clamp, the internally threaded opening being substantially parallel to a longitudinal axis of at least one of the cassette and the tool holder body.